Self-hardening plastic compositions and solid porous bodies prepared thereform



Patented Feb. 23, 1954 SELF--HARDENING PLASTIC COMPOSITIONS AND SOLID POROUS BODIES PREPARED THEREFROM Alvin M. Edmunds,'Midland, Mich, assignor to The Dow Chemical Company, Midland, Mich, a corporation of Delaware No Drawing. ApplicationMarch 24, 1951, Serial No. 217,397

' 15 Claims;

This invention concernscertain'plastic compositions and amethod of making the same. It

pertains especially to plastic compositions which harden, on standing at room temperature, with formation of strong, acid-resistant, solid, porous bodies that are adapted for use as filtermedia, diffusion plates, or spargers, and for related purposes.

The plastic .compositions of theinvention comprise, as essential ingredients, an incompletely condensed thermosetting phenol-formaldehyde resin in a water-insoluble, liquid state, granules or particles of calcined petroleum coke, finer particles of an acid-resistant solid filler, and benzene sulphonyl chloride in the relative proportions hereinafter stated. The calcined petroleum coke, as its name implies, is ordinary petroleum coke that has been heated'at high temperatures, e. in the order of from 800 to 1500 0., advantageously 1 1 00"" to,1400 0., to remove volatile componentsthereirom. It is a solid cellular material; comprising individually closed cells, and constitutes the aggregate in the compositions of the invention. The calcined petroleum coke particles,

or granules, have good strength and are resistant to corrosive attack by acids and alkalies. They are readily wetted and firmly bonded together by the resin. The more finely divided solid filler serves to thicken, i. e. increase the viscosity of, the liquid phenol-formaldehyde resin and to plug minute pores or other openings in the coarser granules of the calcined petroleum coke aggregate. It thereby limits the extent of absorption of the liquid resin by the aggregate granules so that the latter are sizrface-wetted, and'become bonded together, by th resin. Any of a wide variety of finely divided solid materials, such as sand, powdered silica, or quartz, etc, can be used as the filler, but powdered carbon, i. e. ordinary amorphous carbon," and powdered graphite are preferred; The benzene sulphonyl chloride serves as a catalyst, or condensing agent, to cause further condensation, i. e. hardening, of the phenol-- formaldehyde resin which functions as a binder for the particles, or granules, of the calcined petrcleumcoke. The liquid resin, having the filler admixed therewith, is used in amount such as to bond the coke granules together without completely filling the interstices between the granules. The porosity of th hardened article is due to the insterstices; I

The compositions, when hardened, have good dimensional stability, possess good strength, and are resistant to the corrosive action or aqueous acids and salts, etc.,-other than strong oxidizing agents such as nitric-or chromic acid. For in A}! stance, they are not damaged materially .by prolonged contact with sulphuric acid of from 50 to 98 per cent concentration, even at temperatures as high as 175 0. They withstand large and rapid temperature changes without becoming cracked or shattered. However, for obtainment ofa hardened porous article having these desirable properties, it is important that the above-' mentioned starting materials, particularly the calcined petroleum coke and benzene sulphonyl chloride, be employed.

Although numerous materials are known which perform functions of the general types accomplished by the respective essential ingredients mentioned above, and the compositions of the invention may contain other materials in addition to said essential ingredients, no material has been found which may satisfactorily be substituted in place of the calcined petroleum coke, or the benzene sulphonyl ch1oride,to obtain a hardened porous body having the good strength, high acid resistance, thermalshock resistance, and the dimensional-stability that are possessed by the solid porous bodies prepared in accordance with the invention. For instance, the substitution of other kinds of aggregates, e. g. silica pebbles, brick. chips, or ordinary foundry coke obtained from coal, in place of the calcined petroleum coke results in formation of a hardened porous body having considerably less strength and less resistanc to corrosion by aqueous mineral acid solutions than are possessed by the hardened'porous compositions of the invention. The reason for the change in properties of the hardened compositions with change in the kind of aggregate employed is not fullyunderstood, but it is evident that the resin forms a stronger and more permanent bond with calcined petroleum coke than with most other kinds of hard, strong, granular materials. Substitution of para-toluene sulphonyl chloride, hydrochloric acid, sulphuric acid, or other known catalysts for the hardening of phenolforrnaldehyde resins, in place of the benzene sulphonyl chloride which is required by the invention, results in formation of a hardened porous body which becomes corroded to a considerable extent during prolonged contact with aqueous solutions of strong mineral acids, particularly during contact with aqueous sulphuric acid solutions of greater than 50 per cent concentration. Also, such substitution results in production of hardened porous articles which usually continue to undergo appreciable volume changes, i. e. swelling or shrinking, for several months after being formed. As a result of such volume changes, usually-shrinkage, the porous phenol- 3 formaldehyde resin bodies formed by means of catalysts other than benzene sulphonyl chloride often develop cracks on standing.

Although no substances are known which may satisfactorily be used in place of the calcined petroleum coke and the benzene sulphonyl chloride ingredients of the compositions of the invention, the self-hardening plastic compositions may contain various ingredients in addition to those that are required. For instance, the liquid phenolformaldehyde resin ingredient, although substantially insoluble in water, usually contains from 18 to 35 per cent by weight of water dissolved therein. Furthermore, together with the benzene sulphonyl chloride there may be used other catalysts, or condensing agents, such as hydrogen chloride, or trichlorcacetic acid, etc. Mixtures of trichloroacetic acid and benzene sulphonyl chloride, containing at least 40 per cent by weight of the latter, are well suited for use as resinhardening catalysts.

As the resin ingredient, any thermosetting phenol-formaldehyde resin, in a water-insoluble liquid state, may be employed. In general, such resins are prepared by condensation of one molecular equivalent of phenol with between 1 and 2.5, preferably between 1.4 and 1.5, molecular equivalents of formaldehyde and discontinuing the condensation reaction when the product becomes water-insoluble, but remains liquid. Procedures for making such liquid phenol-formaldehyde condensation products (which, though liquid, are commonly termed resins) are well known and need not be given in detail. However, the condensation reaction is preferably started under alkaline conditions, e. g. using from 1 to 2 per cent by weight of sodium hydroxide, potassium hydroxide, sodium carbonate, or other alkali as catalyst and is carried out at temperatures in the order of from .6 to 70 C. to a point at which the product is a fairly thin, water-soluble liquid. The mixture is then acidified by adding a strong aqueous mineral acid such as hydrochloric or sulphuric acid, etc., and the reaction is continued at similar temperatures until the mixture becomes fairly viscous and is waterinsoluble. The reaction is stopped short of the solidification point, since the liquid resin is conveniently used in preparing the compositions of the invention. When the reaction has been carried to the desired stage, the mixture i treated with an alkali, e. g. with an aqueous solution of NaOH, NI-Ea, KOH, NazCOe, or K2003, etc., to bring it to a pI-i value of from 3 to 7 and is washed thoroughly with water. The product, although substantially insoluble in water usually retains a considerable amount, 2. g. from 18 to 35 per cent by weight, of dissolved water. It usually has a viscosity of from 300 to 2,980 centipoises at C., but may be or" lower or higher viscosity. It may be used directly as an ingredient of the compositions of the invention, or it may be aged to further increase its viscosity, in cases where the initial viscosity is undesirably low, prior to such use.

The water which usually remains dissolved in the liquid phenol-formaldehyde resin after preparation of the latter serves as a diluent to extend the covering power of the resin in surface-treating the calcined petroleum coke granules. Accordingly, the proportions of the liquid resincontaining condensation product required for the purpose do not vary greatly with change in its water content, and the proportions of resin herematter stated are inclusive of any water contained therein.

By varying the relative proportions of the aforementioned ingredients, particularly of the liquid resin and calcined petroleum coke, in the plastic composition, the porosity of composition after hardening may be varied in a predetermined manner. Further variations in the porosity of the product may be obtained by changes in the sizes of the coke granules employed in preparing the same. In general, the porosity increases with increase in the average size of the coke granules and decreases with increase in ratio by weight of liquid resin to granular coke of a given size employed in preparing the plastic composition. The

coke granules may be of sizes ranging from 48 mesh to 2 mesh size or larger, based on the Tyler screen scale, but usually are of from 5 to 10 mesh size. The filler, which is used to thicken the liquid resin and to plu any pores in the coke granules, is usually a graded material of from 50 to .00 mesh particle size or finer.

The proportions of filler which may most advantageously be used for thickening the liquid resin vary somewhat with changes in the initial v'mcosity of the resin and with changes in the kind and average particle size of the filler employed. In general, the filler is added to the liquid resin, or to the mixture of a hardenin agent, e. g. benzene sulphonyl chloride, and such resin, in a proportion such that when a cylinder, open on both ends and of 1% inches internal di ameter and 2 inches height, is placed on a horizontal glass plate and filled with the thickened resin, and the cylinder then removed, and contents adhering to the cylinder are scraped therefrom and added to resin adherin to the plate, the resultant column of the thickened resin spreads at a rate such that it has an average diameter of between 2 /2 and 7 inches, preferably between 3 and 5 inches, one minute after removal of the cylinder, and an average diameter of not more than 7, preferably not more than 5 /2 inches, 15 minutes after removal of the cylinder. By an averag diameter is meant the average of two measurements of the diameter taken at a right angle to one another. In most, if not all, instances, the proportions of filler required to thicken the liquid phenol-formaldehyde resin so that the resultant mixture, not containing the aggregate, possesses the above flow rates are within the limits hereinafter given.

The following formulas give the relative proportions, in per cent by weight, of the several essential ingredients in two plastic compositions prepared using calcined petroleum coke of from 5 to 10 mesh grain size; one of which compositions hardens to form a highly porous article and the other of which hardens to form a finely As hereinbefore indicated, the catalyst in eachof the above formulas-may be benzene sulphonyl chloride alone, or a mixture of at least 40 per cent kind of filler employed. using powdered graphite, or powdered carbon as the filler, the several ingredients of the plastic 5 by'weight of benzene sulphonyl chloride together with 60 percent or less of other resin-hardening catalysts, e. g. trichloroacetic acid. The filler may be any solid, inert material in finely divided form, but is preferably powdered carbon, 1. e. ordinary amorphous carbon, or graphite. In general, the plastic compositions of the invention contain the several ingredients in proportions within the limits represented by the above formulas, the optimum proportions in a given instance being dependent upon the average grain size of the coke, the kind of filler employed, and the degree of porosity desired in the compositions when hardened.

In order to obtain hardened articles of about the same tensile strength from successive batches of the plastic composition prepared from similar starting materials, except for a change in mesh size of the calcined petroleum coke used in the diflerent batches, the proportion of the coke,

relative to the other ingredients, should be decreased, within the above-stated limits, with decrease in the average size of the coke granules. A decrease in size of the coke granules employed in making the plastic composition results in rendering the hardened compositions more finely porous.

Within the aforestated general range of proportions in which the several ingredients may be employed in preparing the plastic compositions of the invention, the preferred ranges of proportions vary somewhat with changes in the For instance, when composition are advantageously employed in proportions within the limits expressed by the following formulas for plastic compositions which; when hardened, form highly porous, and porous but nearly impervious, articles, respectively.

Ingredients of Plastic Composition A Porosityof Hard- Calclned Llmiid Gra hite of Petroleum Rosin, Carbon as fi 1 med Article Coke. Wt. Wt. Filler, Wt. Perce'm; Percent Percent Percent 75 11.0 12. 6 1.4 HighlyP'orous. 48.8 23.1 24.3 3.8 l Nearly Impervious.

When using powdered silica as the filler, the plastic compositions advantageously contain their several ingredients in relative proportions within the. limits expressed by the following formulas:

Ingredients of Plastic Composition Porosity of Hard- Calcmed Powdered Catalyst, ened Article 3 3 s, SiOz Wt Wt o c, Percent Percent Percent Percent 68. 6 11. 0 1. 4 EighlyPorous. 50.0 16.9 30 7 2.4 Nearly Impervious.

powdered silica as. the filler for the: plastic com;- positions. Peculiarly, trichloroacetic acid alone, although effective in catalyzing hardening of the resin ingredient, causes formation of porous articles which are severely corroded during pro:- longed contact with aqueous acids, especially concentrated sulphuric acid, and is not satisfactory for the purpose of the invention. Benzene sulphonyl chloride alone, and the mixtures thereof with 60 per cent by weight or less of trichloroacetic acid, are eifective as catalysts for hardening the compositions to form strong, acidresistant, porous articles.

The optimum proportions of catalyst in the plastic compositions, and the relative proportions of benzene sulphonyl chloride and trichloroacetic acid which may most advantageously be present in the catalyst, vary somewhat depending upon whether powdered silica, or either powdered carbon or powdered graphite, is used as the filler ingredient of the composition. When using powdered carbon, or powdered graphite, or a mixture thereof, as the filler, there is preferably employed from 1.4 to 3.8 per cent by weight of a catalyst consisting predominantly of benzene sulphonyl chloride, but which may contain up up to 60 per cent by weight of trichloroacetic' acid. When using powdered silica as the filler, there is preferably employed, as the catalyst, from 1.4 to 2.4 per cent by weight of a mixture of from 45 to 75 parts by weight of benzene sulphonyl chloride and from 55 to 25 parts of trichloroacetic acid.

The hardened compositions containing powdered carbon or graphite as the filler are usually stronger and more resistant to corrosive attack by acids and alkalies than are the compositions containing silica as the filler. However, the compositions containing silica as a filler possess good strength and good acid-resistance and can be manufactured at lower cost than those containing graphite or carbon as the filler. Products having properties intermediate of those of the respective articles just mentioned may be obtained by using mixtures of silica and carbon and/0r graphite as the filler. In practice, powdered graphite, or powdered carbon, or a mixture thereof is preferred.

The manner in which the aforementioned ingredients are admixed maybe varied somewhat, but the ease of mixing to obtain asubst'antially uniform plastic composition varies with changes in the order and manner of bringing the ingredients together. It is important that the catalyst and the liquid phenol-formaldehyde resin be admixed shortly before the plastic composition is troweled, rolled, tamped, or otherwise shaped, since the. catalyst causes fairly rapid hardening of the resin. Itis also important that the filler be admixed with the resin prior to adding the granular calcined petroleum coke. Otherwise, the coke absorbs an excessive amount of the resin. Furthermore, it. is important that the coke be added in. large portions to the mixture of the resin, filler, and catalyst, with stirring between the additions, since otherwise the mix.- ture tends to form-balls, or agglomerates, which are diiiicult to break up so as to obtain a-uniform composition. Usually, from A; to /2, preferably about of the colre is added to a mixture of the other ingredients and is stirred into the mixture. Thereafter, the remainder of the coke is added in large portions with stirring. In practice, it has been found most satisfactory to add the coke as from three to'four about equal-sized portions with stirring of the mixture after each addition.

Except for the precautions just mentioned, the manner of mixing the ingredients may be varied considerably. Usually, the catalyst is admixed with the liquid resin, after which the filler is added to thicken the resin. The calcined petroleum coke is then added. Alternatively, the filler may be Wetted with the catalyst and thereafter be admixed with the resin. The mixture of filler and catalyst may be stored, or shipped to a point of use, and when desired be mixed with the other ingredients.

The plastic composition solidifies and hardens at room temperature in a period of from about /2 hour to several hours after it is formed. Hardening may be accelerated by warming the mixture. It is, of course, important that the .-operations of forming and shaping the mixture be completed before hardening occurs. The plastic composition may be shaped by usual operations such as troweling, rolling, or tamping, etc. During troweling, the trowel, or other tool may advantageously be wiped from time to time with a cloth moistened with alcohol, or other solvent for the resin. This prevents sticking of the composition to the tool. Prior to rolling or tamping the composition, the latter may be covered with a flexible metal sheet, e. g. of iron, coated on the underside with petrolatum, or the like, to prevent sticking. After the rolling or tamping operation, the sheet is removed and the composition ermitted to harden in place.

Once hardened, the composition does not undergo further shrinkage or swelling to an 013- containing graphite or carbon as the filler are not only acid-resistant, but possess good resistance to the corrosive action of dilute aqueous alkalies, provided conditions are alternately acidic and alkaline. Regardless of the kind of filler employed, the hardened porous articles prepared in accordance with the invention have good tensile strength, e. g. in the order of from 85 to 1000 pounds per square inch or higher. Such articles prepared under the preferred conditions hereinbefore given, usually have a tensile strength in the order of from 700 to 1000 pounds per square inch.

The following examples describe a number of ways in which the invention has been practiced, and illustrate certain of its advantages, but are not to be construed as limiting its scope.

EXAMPLE 1 per pound of the mixture to which the acid was added. The acidified mixture was agitated. while warmed to about 40 C. for from 2 to 3 hours. The aqueous and organic layers of the mixture were separated. The organic layer was neutralized to a pH value of from 3.4 to 7.0 by treatment with sodium hydroxide, and washed thoroughly with water. The water-insoluble, liquid phenol-formaldehyde condensation prodnot, thus obtained, retained from 18 to 35 per cent of water dissolved therein.

EXAMPLE 2 Approximately 2.34 parts by weight of benzene sulphonyl chloride was dissolved in 19.16 parts of a liquid phenol-formaldehyde condensation product similar to that described in Example 1. The solution was thickened by admixing therewith 21.5 parts of graded graphite powder ranging from 50 to 400 mesh particle size. To the resultant mixture there was added, as three approximately equal-sized portions, 5''! parts of calcined petroleum coke in the form of granules of from 5 to 10 mesh size. The mixture was stirred thoroughly during and after each such addition. The resultant plastic composition was shaped into plates, bars and briquettes which, after becoming hardened, would be suitable for use in determining properties of the composition. The test plates were of 1 inch thickness. The test bars were of 1 inch square cross section and of approximately 10 inches length. Each briquette was 1 inch thick and of 1 inch square cross section at the midpoint of its length. The end portions of the briquettes were widened in a tapered manner to permit gripping of the same. After being formed, the test pieces hardened on standing at room temperature for from 3 to 5 hours. When a test bar had stood at room temperature for about 24 hours after becoming hardened, its length was measured. The bar was then permitted to stand for 30 days and its length was again measured. It was found that the bar had shrunk by only 0.104 per cent of its original length during the 30 days of standing, i. e. the hardened bar possessed good dimensional stability. Thirty days after it had been formed and hardened, a briquette of the composition was tested to determine its tensile strength. It was found to have a tensile strength of 915 pounds per square inch of cross section at the point of breakage. Thirty days after they had been formed and hardened, two test plates of the composition were separately tested to determine their permeability to water. In each test, water, under a pressure corresponding to a head of 1 foot of water, was fed to a measured area of one face of a plate, and the rate of flow of water through the thickness of the plate was measured. The permeability values thus found for the two plates, each of 1 inch thickness, were 17.34 and 18.2 gallons of water per minute per square foot of plate area, respectively.

EXAMPLE 3 A number of plastic compositions were prepared as described in Example 2, except that the relative proportions of the several starting materials were varied from one composition to another. Each composition was shaped into test plates and briquettes, as in Example 2, and the test pieces permitted to harden. Seven days after being formed and hardened, the briquettes were tested to determine the tensile strength. Thirty days after being formed and hardened the plates were tested, as in Example 2, to deter- 9 mine theirpermeahility to water. The tollowing table gives the relative proportions, in per cent by weight. of the liquid phenolformaldehyde condensation -product, the benzene sulphonyl chlo- 10 It also gives the properties which were determined for the hardened composition. In the table, the liquid phenol-formaldehyde condensation product is referred to as P. F. resin.

Table II Ingredients of Composition, Percent by Wt. Hardened Composition Run No; 1 Benzene d Tensile 30 Days Water-Perme- P. F. Tncliloro- Powdered Calcinecl t Sulphonyl Srength, Percent ability, gaL/ R231 Chloride Gmphte ggf lbs/sq. in. Shrinkage min/San.

19. 55 4 2. 52 0. 86 22. 07 55. U 960 0. 068 7. 5 18. 66 2.40 0. 83 21. 11 57. O 915 0. 040 28. 5 17.38 2. 24 0. 77 19. 61 (30. 605 0.150 36. 6 15.20- l. 96 0.67 17. 17 65. 0 365 0.105 62. 3 13.0 1. 68 .o. 57 14. 75 70. o 180 0. 077 10. 86 1. 4.0 0. 48 12. 26 75.0 95 95. 0

. Not determined.

ride, the powdered graphite and the calcined EXAMPLE petroleum coke used in preparing each composition. It also gives the tensile strength, in pounds Two plastic compositions were prepared as in Example 2, except that powdered silica of from 80 to .400 mesh size and finer, instead of powdered graphite, was used a a filler and that the relative proportions of the several ingredients were varied from one composition to the next. The plastic compositions were shaped into test pieces which hardened on standing for from 3' Table I Ingredients of Composition, Percent by Wt. i Hardened Composition l o Benzene P d d 6 Tensile Water-Perme- P. ow are a c e snlphonyl v Strength ability gaL/ Resin Chloride I Graphite B25351? lbs/sq. m. min San.

1 20. 04 2. 22. 51 55 949 5 12.0 2 17. 82 .2. 13 20.0 1 I 622 I 40. 4 3 15. 60 1.91) 11. 5 r 55 358 55.7 4 11.13 1.36 12.51 '85 81. 9

EXAMPLE 4 to 5 hours. Thirty days after being formed and hardened, the test pieces were employed in determining the tensile strength and waterpermeability of each composition, as in Example 2. Table III :names and gives the relative proportions, in per cent by weight, of the ingredients of each composition. It also gives the tensile and that the relative proportions of the several 50 strengthand'the water-permeability values found starting materials were varied from one comfor the hardened composition.

Table III Ingredients, Percent .by Wt. Hardened Composition Rim I v No. Benzene J 5 M Tensile Water-Perme- P. I. Tnchloro- Powdered calcined Sulphonyl, Strength ability 'gaLl Beam Chloride .acetlc gfif 1bs./sq.in. mill/8:1. a.

position to another. Each composition was EXAMPLE 6 shaped into plates, bars and briquettes-for use in determining its properties and the test pieces were permitted to harden and were used to determine the tensilezstreng-th, the per cent shrinkage .in .a-period or thirty days after hardening, and the water-permeability of the composition, as in Example 2. The tensile strength and waterpermeability values were determined using test Pieces that had stood thirty days after hardening. Table II names and gives the relative proportions-in per cent by weight, of the several inused in preparing reach composition.

it was necessary to vary the relative proportions of the several starting materials used in making the compositions and, in some instances to change somewhat the average grain size of aggregate material in substituting one kind of an aggregate for another. Table IV names, and gives the proportions in per cent by weight of, the ingredients used in making each composition. It indicates the range of sizes of the granule of aggregate used in each composition. The 10 table gives the water-permeability value and the tensile strength of each hardened composition. The tensile strength values were determined the acid. An increase in tensile strength is indicated by a plus sign and a decrease by a minus sign. The abbreviations P. F. resin and "Gale. Pet. Coke have the same meanings as in preceding examples.

In the table,"P. F. resin pertains to the liquid phenol-formaldehyde condensation product employed in preparing the compositions and Gale. Pet. Coke is an abbreviation of calcined petroleum coke.

Table V Ingredients, Percent by Wt. Tensile Strength l Filler .No. P F Benzene Trichloro- Cale. Before Acid Alter Acid Peri Sulphqnyl acetic Pet. Treatment, Treatment, cent Ohlonde Acid Kind Pts Coke lbs/sq. in. lbs/sq. in. Change 1 20. 05 2. 45 None Graphite 22. 5 55. 730 772 +5. 4 2 21. 38 2. 62 None 0 16. 0 6D. 0 614 482 2l. 3 21. M 1. 35 1. 86 do 20. 55. 0 924 763 17. 4 4 24. O5 2. 95 None S102 18. 0 55. 0 660 749 -l3. 5 5 i5. 53 None 2. 74 do 26. 73 55. 0 588 308 47. 6 6 11.90 None 2.10 -do 26.0 60.0 197 132 --33. 0

seven days after hardening of the compositions. EXAMPLE 8 A number of plastic compositions were prepared by dissolving a minor amount of benzene sulphonyl chloride in separate portions of a liquid phenol-formaldehyde condensation prod- Table IV Ingredients, Percent by Wt. Hardened Composition Run Aggregate i N o. P F Benzene Trichloro- Water-Perme- Tensile i Suiphonyl acetic Graphite ability, gal./ Strength, Chloride Acid Kind Amount mmJsq. ft. lbs/sq. 1n.

I-a 19.16 2. 34 21. 5 Oslo. Pet. Coke 5-10 57.0 17.77 958 Ib 11.58 1. 42 13. 0 4-5 74. 0 19. 46 510 Ic 9. 26 1.13 10.37 Quartz 0 4-6 79. 24 17. 30 20c II-a 18. 66 2. 21. 11 Cale. Pet. COkc 5-10 57.0 28. 5 1125 II- 11. 35 1. 12. 7 Brick Chips. 5-10 74. 0 28. 2 359 II-c, 8. 23 1. ()0 9.23 Fused B'Igo 4-8 81. 54 28. 3 229 II-d", 13.4 1. 64 15. 06 A120: 4-6 69. 9 26. 7 96 III-a 17. 82 2.18 20.0 Cale. Pet. Cok 5-10 60. 0 40. 4 550 III-0.. 6. 88 0. 84 7. 72 S102 Pebbles" 4-6 84. 56 38. 0 127 IV-a 15. 60 1.91 17. 5 Cale. Pet. Goke 5-10 65.0 55. 7 447 IV-b 20. 05 2. 44 22.5 Foundry Goke. 5-10 55. 0 63. 1 205 EXAMPLE 7 This example is presented to illustrate the stability which the hardened compositions of the invention possess against detrimental attack by 55 sulphuric acid at an elevated temperature. For comparative purpose, the example includes tests of compositions which were prepared without use of benzene sulphonyl chloride and are therefore outside the scope of the invention, but are otherwise similar to the compositions of the invention. Table V names and gives the relative proportions, in per cent by weight, of the ingredients used in each composition. Except for the kinds and proportions of the starting materials not, similar to that described in Example 1, and thickening each solution by admixing powdered graphite of from 50 to 400 mesh particle size therewith. To each of the thickened solutions, a granular aggregate, of between 4 and 10 mesh grain sizes, was added in three equal portions with stirring of the mixture during and after each addition. The compositions difiered from 60 one another as to the kind of aggregate employed and as to the relative proportions in which the several starting materials were used. Each plastic composition was shaped into briquettes,- as described in Example 2. hardened on standing atroom temperature for from 3 to 5 hours. Approximately 9. week after it was formed and hardened, a briquette of each composition was tested for tensile strength. Another hardened briquette of the same composition was immersed in a heated bath of an aqueous hydrochloric acid solution of 20 per cent concentration and was maintained in the bath for 30 days. Throughout this period, the bath was heated at a temperature of 110 C. -At the end-ofsaid period, the briquette was removed- The briquettes from the bath, washed with water, and tested for tensile strength. Table VI names and gives the relative proportions, in parts by weight, of the several. ingredients used in preparing each composition. It also gives the tensile strength, inpounds per square inch of cross section of each hardened composition both before and after the treatment with acid. The table gives the per cent by which the tensile strength of each compo sition was changed by the treatment with acid. In the table, an increase in tensile strength is indicated by a plus sign and a decrease in strength is indicated by a minus sign.

ing chamber, the inserts were removed to clear the channel passages, and the chamber. was; placed in service. The treatment involves filling the chamber with a crude sulphonation mixture consisting of a slurry of a solid .sulphonated hydrocarbon material in sulphuric acid of about 86 per cent concentration. The slurry is at a Table VI Ingredients, Percent by Wt. TensileStrength Run I l No. P F Benzene Aggrebate Before Acid AfterAcid Peri g ,Sulphonyl Graphite Treatment, Treatment, cent Chloride Kind Amount lbs./sq.in. 1bs./sq.in. 1 Change 20. 05 2. 45 22. 5 Oalc. Pct. Coke... 55. 0 are 1163 +215 19. 2. 35 21. 5 Foundry Coke 57. 0 245 266 +8. 6 11.58 1. 42 13.0 Brick Chips 74. 0 5% 344 3 3 9. 1.13 10. 38 Quartz 79.2 222 Q. 18 1.12 10.30 Silicon Oarb1de 79. 4 291 100 6 8. 23 1.00 9. 23 Fused MgO 81. 54 295 53 7 go 1 6. 88 O. 84 7. 72 Crystalline A12o3 84. 56 3 45 0 EXAMPLE 9 temperature of about 70 C. when fed to the This example shows use of a large filter plate,

prepared in accordance with the invention, as the bottom of a chamber for treatment of a crude sulphonation mixture. The filter plate is used for flow of liquors to and from the chamber at temperatures which vary widely at different stages in the treatment. Also, the treatment is one whichlnvolves consecutive passage of concentrated sulphuric acid, diluted sulphuric acid, water, and an aqueous alkali solution through the;fi1ter plate. example includes data collected during an earlier use, in the same treatment, of a filter plate of similar size and shape, but not prepared in accordance withthe invention. Each of the filter plates was in the form or a panel having'channels connecting with a valved main pipe which extended through a wall of the chamber and served forfiow ofliquids to and from the cham ber. Each panel was l /2 inches thick and was intheform of a 6 foot x 6 foot square. Such panel, which served as a pervious bottom for the chamber, rested on an impervious, corrosionresistant base. The filter'plate which was first used; and was not made in accordance with the invention, was made by admixing calcined petroleum coke of from 5 to 10 mesh size with a mixture of a liquid phenol-formaldehyde resin and a filler (having a catalyst, i. e. a resin-hardening agent, admixed therewith) which had been purchased on the market. The catalyst which it contained was not benzene sulphonyl chloride. In making the second filter plate, a plastic composition was prepared in accordance with the invention by mixing 2.34 parts by weight of benzene sulphonyl chloride with 19.16 parts of a liquid phenol-formaldehyde condensation prodnot, similar to that described in Example 1, and thickening the mixture by adding 21.5 parts of powdered graphite of from 50 to 400 mesh size. Fifty-seven parts of granular calcined petroleum coke of from 5 to 10 mesh size was added in three equal portions with stirring during and after each addition. A 4 inch layer of the resultant plastic composition was spread at the bottom of the chamber around removable in- For purpose of comparison, this chamber. phonated product through the filter plate-and the center outlet pipe embedded therein. Vacu'.

umis applied to aid in removing the acid. When most of the acid has been removed, water is sprayed from above onto the sulphonated material and the resultant dilute sulphuric acid solution is, at the same time, drained from the mixture through the filter plate serving as a bottom to the chamber. During this operation, the-temperature of the liquor flowing from the chamberrises spontaneously, in about 20- minutes, from approximately 70 C. to about C. As the washing is continued, the temperature then decreases. After thoroughly washing the sulphonated product with water to remove the sulphuric acid therefrom, an aqueous sodium -carbonate solution of about 10 per cent concen-' air admitted through the porous bottom of the chamber. The aqueous solution of unspent'sodium carbonate, and/or bicarbonate, is drained from the product through the porous bottom to the chamber, after which the product is againwashed with water and the washings removed in similar manner. The product is then removed from the treating chamber and the latter is reemployed to treat a subsequent batch of the sulphonation mixture. Such repeated use of the chamber is continued until the filter plate, used as a bottom thereof, cracks, breaks, or crumbles. The aforementioned filter plate, made from a composition outside the scope of the invention, became so badly cracked after 34 days of such use, as a bottom of the treating vessel, that it had to be removed and replaced. In contrast, the filter plate, made from the composition prepared in accordance with the invention, withstood 113 days of similar use as a bottom to the treating vessel before replacement was necessary.

Other modes of applying the principle of the invention may be employed instead of those explained, change being made as regards the The acid is drained from the sul-:

715 method or compositions herein described, provided the steps or ingredients stated by any of the following claims or the equivalent of such stated steps or ingredients be employed.

I claim:

1. A plastic composition, having a property of hardening at room temperature to form a rigid, porous, acid-resistant article, which composition comprises a mass of calcined petroleum coke granules having outer surfaces thereof wetted with a mixture of a liquid, thermosetting phenolformaldehyde condensation product, a resinhardening catalyst comprising at least 40 per cent by weight of benzene sulphonyl chloride, and a substantially inert, finely-divided filler in amount sufiicient to thicken the liquid phenolformaldehyde condensation product and thus limit absorption of the same by the coke granules, said phenol-formaldehyde condensation product being present in amount sufficient for surface-wetting of the calcined petroleum coke granules, but insufficient to fill completely the interstices between said granules.

2. A composition, as described in claim 1, wherein the calcined petroleum coke granules are from 2 to 48 mesh size and the filler is of from 50 to 400 mesh particle size.

3. A composition, as described in claim 2, wherein the catalyst is benzene sulphonyl chloride.

4. A composition, as described in claim 2, wherein the catalyst is a mixture of trichloroacetic acid and benzene sulphonyl chloride containing at least 40 per cent of the latter.

-5. A composition, as described in claim 2,

wherein the filler is selected from the group consisting of graphite, non-graphitized carbon, and mixtures thereof.

6. A composition, as described in claim wherein the filler is silica.

7. A composition, as described in claim 1, wherein the calcined petroleum coke is in the form of granules of from 5 to mesh size and the composition comprises from 41.6 to '75 parts by weight of such coke, from 23.1 to 11.0 parts of the liquid phenol-formaldehyde condensation product, from 31.5 to 12.6 parts of the filler in the form of particles of from 50 to 160 mesh size, and from 3.8 to 1.4 parts of the catalyst.

8. A lastic om osition, havin a re ert f p c p g p p y 0 ture of the other ingredients, stirring the mixhardening at room temperature to form a rigid, porous, acid-resistant article, which composition comprises an intimate mixture of from 48.8 to 75 per cent by weight of calcined petroleum coke in from 23.1 to 11 per cent of a liquid, thermosetting containing at least 40 per cent by weight of benphenol-formaldehyde condensation product, from 24.3 to 12.6 per cent of a filler selected from the group consisting of graphite, non-graphitized carbon, and mixtures thereof in the form of particles of from 50 to 400 mesh size, and from 3.8 to 1.4 per cent of a resin-hardening catalyst containing at least per cent by weight of benzene sulphonyl chloride.

9. A plastic composition, having a property of hardening at room temperature to form a rigid,

acid-resistant porous article, which composition comprises an intimate mixture of from to 68.6 per cent by weight of calcined petroleum coke in the form of granules of from 2 to 48 mesh size, from 16.9 to 11.0 per cent of a liquid thermosetting phenol-formaldehyde condensation product, from 30.7 to 19.0 per cent of silica in the form of particles of from 80 to 400 mesh size, and from 2.4 to 1.4 per cent of a resin-hardening catalyst containing at least 40 per cent by weight of henzene sulphonyl chloride.

10. A composition, as described in claim 9, wherein the catalyst contains from 45 to 75 per cent by weight of benzene sulphonyl chloride and from to 25 per cent of trichloroacetic acid and is present in amount corresponding to from 2.4 to 1.4 per cent of the weight of the composition.

11. A rigid, porous article consisting of the composition of claim 1 in hardened condition.

12. A rigid, porous article consisting of the composition of claim 8 in hardened condition.

13. A rigid, porous article consisting of the composition of claim 9 in hardened condition.

14. A rigid, porous article consisting of the composition of claim 10 in hardened condition.

15. A method of making a rigid, acid-resistant, porous article which comprises admixing, with a liquid, thermosetting phenol-formaldehyde condensation product, a resin-hardening catalyst zene sulphonyl chloride, and a substantially inert, finely-divided filler in amount sufficient to thicken the condensation product, and thereafter adding calcined petroleum coke granules of from 2 to 48 mesh size in amount such as to be surface- "wetted by the liquid phenol-formaldehyde condensation product without complete filling of the interstices between said granules, the last-mentioned addition being made by adding as a single portion about one-third of the coke to the mixture, and thereafter adding the remainder of the coke with stirring, shaping the resultant composition, and causing it to harden by standing. ALVIN M. EDMUNDS.

No references cited. 

1. A PLASTIC COMPOSITION, HAVING A PROPERTY OF HARDENING AT ROOM TEMPERTURE TO FORM A RIGID, POROUS, ACID-RESISTANT ARTICLE, WHICH COMPOSITION COMPRISES A MASS OF CALCINED PETROLEUM COKE GRANULES HAVING OUTER SURFACES THEREOF WETTED WITH A MIXTURE OF A LIQUID, THERMOSETTING PHENOLFORMALDEHYDE CONDENSATION PRODUCT, A RESINHARDENING CATALYST COMPRISING AT LEAST 40 PER CENT BY WEIGHT OF BENZENE SULPHONYL CHLORIDE AND A SUBSTANTIALLY INERT, FINELY DIVIDED FILLER IN AMOUNT SUFFICIENT TO THICKEN THE LIQUID PHENOLFORMALDEHYDE CONDENSATION PRODUCT AND THUS LIMIT ABSORPTUON OF THE SAME BY THE COKE GRANULES, SAID PHENOL-FORMALDEHYDE CONDENSATION PRODUCT BEING PRESENT IN AMOUNT SUFFICIENT FOR SURFACE-WETTING OF THE CALCINED PETROLEUM COKE GRANULES, BUT INSUFFICIENT TO FILL COMPLETELY THE INTERSTICES BETWEEN SAID GRANULES. 